How do I search and retrieve arXiv academic papers via MCP?

@fre4x/arxiv — arXiv MCP Server (stdio, credential-free)

Package: @fre4x/arxiv v1.1.6 · npm Transport: stdio Auth: None required — arXiv API is fully open Install: npm install @fre4x/arxiv Entry: node node_modules/@fre4x/arxiv/dist/index.js

Tools (5)

Verified Traces (7 calls, all successful)

1. search_papers — keyword search

// Request
{"name":"search_papers","arguments":{"query":"large language model agents tool use","max_results":3}}
// Response (4533ms): 2,162,505 results found
// First hit: "Learning From Failure: Integrating Negative Examples when Fine-tuning LLMs as Agents" (2402.11651)

2. search_papers — different query

{"name":"search_papers","arguments":{"query":"transformer attention mechanism","max_results":2}}
// Response (1017ms): 472,564 results
// First hit: "Transformer-based Personalized Attention Mechanism for Medical Images" (2206.03003)

3. get_paper — single paper by ID

{"name":"get_paper","arguments":{"ids":["2310.06825"]}}
// Response (2449ms): Mistral 7B paper, authors, abstract, PDF link, categories

4. get_paper — batch retrieval (multiple IDs)

{"name":"get_paper","arguments":{"ids":["2310.06825","1706.03762"]}}
// Response (519ms): Both papers returned — Mistral 7B + Attention Is All You Need

5. search_by_author

{"name":"search_by_author","arguments":{"author":"Yann LeCun","limit":2}}
// Response (442ms): 2,110 results. First: "Introduction to Latent Variable Energy-Based Models" (2306.02572)

6. search_by_category

{"name":"search_by_category","arguments":{"category":"cs.AI","limit":2,"sort_by":"submittedDate"}}
// Response (325ms): 187,398 results. Returns latest submissions in cs.AI

7. list_categories

{"name":"list_categories","arguments":{"limit":5}}
// Response (99ms): cs.AI, cs.CL, cs.CV, cs.LG, cs.NE with descriptions

Gotchas

• get_paper takes ids as an array, not a single string — {"ids": ["2310.06825"]} not {"paper_id": "2310.06825"}
• search_papers returns 20 results by default even if you pass max_results — the server param is actually limit
• Server prints "arXiv MCP server running on stdio" to stdout on startup — harmless, does not break the protocol
• Latency ranges 99ms (list_categories) to 4533ms (broad search) — arXiv API speed, not server overhead

MCP Client Config

{"mcpServers":{"arxiv":{"command":"node","args":["node_modules/@fre4x/arxiv/dist/index.js"]}}}